You have a coupon to purchase a graphing calculator worth $20. When you get to the store you find that they are offering 15% off calculators. But, you can't use your coupon. This makes you wonder what the cost of a calculator would be for your coupon and the 15% off discount to be the same. Find the original price of a calculator where you would pay the same amount whether you used the coupon or got the discount. Write an equation you can use to solve the problem. Define your variable. (Tell me what the variable in your equation represents.) Explain how you arrived at your equation and how it models the problem.
Finally, explain how to solve the equation and what the solution is.